These are the real deal, Autocraft 910 heads, valve covers, and manifolds.

Heads and valve covers are used, but unported and in very good shape. Intake manifolds are brand new, genuine Autocraft versions.

94mm bore, .425" step from outer fin to sealing surface (unknown chamber volume). Includes used Manley stainless steel single groove valves - 11/32" stem diameter, ~49.25mm intakes and ~39.25mm exhausts, steel retainers & keepers. Guides are not loose or sloppy and seats look good. Valves may be usable, but I'd suggest at least a valve job, if not the purchase of new valves. The corner of one fin was cracked, but rewelded - otherwise heads show no other problems or signs of abuse.

Decided to do some valve lapping to see how the sealing surfaces of the valves and seats are. Looks pretty good to me:

Here's a shot of the retainers, locks, and springs. The heads are cut for Chevy-style/size springs (i.e., K800's) - .775" ID and 1.460" OD. I reassembled the heads, but wouldn't re-use the springs as they've got some pitting in a number of areas.